Gas burner nozzle



Jan. 12, 1932.

G. KEITH GAS BURNER NO ZZLE Filed April 29, 1929 Patented Ja 12, 1932UNITED STATES PATENT OFFICE GEORGE KEITH, OF LONDON', ENGLAND, ASBIGNOBTO THE SURFACE COMBUSTION COK- I PANY, INCORPORATED, 015 NEW YORK, N.Y., A CORPORATION OF NEW YORK GAS BURNER NOZZLE ag ncmon am April 29,1929. mm No. 858,858.

This invention relates to improvements in gas burner nozzles for usewith a self-burning mixture of as and an, as employed for example ingas-flredbread and biscuit ovens.

overheated on account of the com aratively low velocity of issue. It isthere ore requisite to fitto the burner tube, which is itself enclosedwithin an outer tube shut oif from the baking-chamber, a series ofnozzles having outlets allowing for a comparatively high velocity ofissue. Even so, the requirement that the nozzles shall be of some metalcapable of working at red heat without oxidizing restricts the range ofpracticable designs.

In practice itis found that chromium steel alloy, containingapproximately 12% of chromium, withstands very well the temperatureconditions, so that the problem to be solved was to devise a burnernozzle which can be readily produced on a manufacturing scalenotwithstanding the hardness and toughness of the metal, which is notliable to light back when using a highly heated selfburning mixture evenwhen turned low down, which does not permit the flame to blow off, andwhich is free from tendency to whistle.

These and other requirements are satisfied by the nozzle of the presentinvention.

In the accompanying drawings Fig. 1 is a part vertical section and Fig.2 a plan showing an assembled burner nozzle constructed in accordancewith the invention; Figs. 3, 4 and 5 are detail views showing the innerelements of the burner detached.

The nozzle shown comprises an externally screw-threaded nipple 1 in thetubular bore 2 of which are located a solid cylindrical plug 3 and anannular retaining collar 4, the plug 3 being confined between the innerend face 5 of the collar 4 and an inwardly extending shoulder 6, theshoulder forming the boundary of the circular aperture 7 The plug 3constituting the-burner head is formed with four pairs of saw cuts orslots 8 extending from the periphery to a short distance from the axisand disposed skew to the latter so that rotational motion is imparted tothe flames issuing therefrom. The upper end of the collar 4 is chamferedat 9 so as to ex ose a maximum slot area on the lower end 0 the plug 3.

In assembling the nozzle, the plug and the collar are inserted into thenipple 1. The lower edge 11 of the nipple is then beaded over thechamfered lower edge 10 of the collar so as to hold the whole togetheras shown in Fig. 1. To provide a sharp lower edge for beading, the lowerend of the nipple is chamfercd at 12.

13 denotes a cylindrical portion depending from the plug 3 andincidental to the mode of manufacture of the plugs which are machined inpairs, dumb-bell fashion, the parts forming a pair being interconnectedby a member of which the cylindrical portion 13 constitutes one half.When the parts are' separated, the cylindrical portions I?) affordgripping arbors during the subsequent slotting operation. The plug 3 isexternally screw-threaded to permit convenient chucking of the blankfrom which a pair of plugs is formed.

The upper portion 14 of the nipple 1 is of polygonal cross section forengagement by a spanner, key or the like for use in screwing the nozzleinto the wall of the burner tube.

It is found that the rotation of the flames effected by the skewarrangement of the slots prevents the flames from being blown ofi thenozzles and also prevents whistling due to incipient blowing off.Apparently the flames are thrown outwardly against the wall of theshoulder portion 6, which prevents the entrainment of inert products ofcombustion from the immediately surrounding region.

The rotation of the flames results in enlarging the area of the portionof the outer tube on which the flames impinge so that the outer tube isnot heated in small spots only.

I claim A gas burner nozzle comprising a nipple presenting a borerestricted at one end by an r a for the root 838 internal shoulder,presenting a lateral bound- Egrtion of the gas flame, a tantially cydrical solid stationa plug fitting said bore and abutting at one en onsaid shoulder, said plug formed with narrow tan ential slots extendingthe entire length 0? said plug from the peri hery to a short distancefrom the axis an disposed skew to the axis, said plu having no passagefor gas other than said slots, said end of said plug limiting the baseof the flame and a collar disposed within said bore engaging theopposite end of the plug and confining the plu within said bore, saidparts geing made 0 metal non-oxidizable under eat.

In testimony whereof I have signed my name to this specification.

GEORGE KEITH.

